Preparation and characterization of a p-tert-butyl-calix[6]-1,4-benzocrown-4-bonded silica gel stationary phase for liquid chromatography

High-performance liquid chromatography of di- and trisubstituted aromatic positional isomers on 1,3-alternate 25,27-dipropoxy-26,28-bis-[3-propyloxy]-calix[4]arene-bonded silica gel stationary phase

“…1. Based on the chromatographic data, the 1,3-Alt CalixPr has reversed-phase property and exhibits strong retention power, which is similar in many cases to the calixarene stationary phases synthesized by the other research groups [16][17][18]25,26]. It can be shown that separation of positional isomers, for example ortho-, metaand para-nitroaniline, which only partly succeeded with ODS stationary phase, can be executed very well with the novel phase used in the present study.…”

“…Several previous works have shown that calixarene-bonded stationary phases possessing including capability are excellent in reversed-phase chromatography. Some research groups [16][17][18][24][25][26] described application of these phases in separation of analytes of very similar structure, e.g. aromatic positional isomers, by HPLC.…”

“…Park et al [16] synthesized calyx [6]arene-p-sulfonate-bonded silica stationary phase and carried out separation of aromatic positional isomers. Gebauer et al [17][18][19] reported the chromatographic separation of disubstituted aromatics, nucleosides, uracil derivatives, estradiol epimers and cis/trans isomers of proline-cointaining peptides on calix[n]arene-bonded (n = 4, 5, 6,8) from Wuhan University (Xiao and coworkers) prepared p-tert-butyl-calix [6]arene-bonded silica gel stationary phase with 3-glycidoxypropyltriethoxysilane [20] and p-tert-butylcalix[n]arene bonded (n = 4, 8) silica gel stationary phases with ␥-(ethylenediamino)-propyltriethoxysilane as coupling reagents [21][22][23][24][25] and carried out the chromatographic separation of some positional isomers, polycyclic aromatic hydrocarbons (PAHs), nucleosides, sulfonamides, quinolones and aromatic carboxylic acids. Sokoließ et al compared selectivity of unsubstituted calixarenes of different ring size by separations of PAHs, barbituric acids and benzoxepin derivatives, xanthines and cis/trans isomers of thioxanthene and discussed the influences of binary eluents on the retention behavior [26][27][28].…”

Synthesis and application of p-tert-butylcalix[8]arene immobilized material for the removal of azo dyes

“…Moreover, silica deserves particular attention due to the hydrophilic surface and presence of silanol groups which are weakly acidic and are very reactive and by virtue of hydrophilic character, the silica surface physically sorbs water molecules. Such property indicates that on modification with calixarene moieties, silica surface permits interaction with various organic dyes [24][25][26][27][28].…”

Calixarene-engineered surfaces and separation science

“…n = 4, 5, 6 and 8) as HPLC stationary phase has been extensively studied [14,27,39,42,77,78]. (ii) The test compounds ranges from aromatic compounds to nucleosides, nucleobases, PAH, fullerenes, drugs, alkali metal ions, vitamins, steroids, etc.…”